Not Applicable.
The present invention relates generally to dehumidifiers, and more particularly, to devices for reducing the relative humidity in enclosures.
Challenges associated with maintaining relatively low moisture levels within enclosures containing electronic assemblies are well known to one of ordinary skill in the art. For example, it is known that condensation within a sealed unit containing electronic components accelerates corrosion of the components. Harsh environmental conditions, e.g., relatively large temperature swings, salty air, and airborne contaminants, can accelerate corrosion effects.
Various attempts have been made to decrease the moisture levels within sealed electronic enclosures. In some cases air conditioning is used to reduce humidity. However, air conditioning is relatively heavy, costly, noisy and unreliable. Desiccants placed in a sealed enclosure may have some initial success in reducing moisture levels, but will inevitably become saturated and, therefore, ineffective. Other attempts include the use of blower fans and temperature controllers. While heating the air within the enclosure may lessen the relative humidity, moisture within the air is not removed. In addition, fans are mechanically and electrically noisy which can degrade the performance of the electronics within the enclosure. Further, temperature controllers have a limited useful life since they contain active components.
It would, therefore, be desirable to provide a relatively quiet and reliable dehumidifier that removes moisture from the air within a sealed electronic enclosure.
The present invention provides a thermoelectric dehumidifier that passively reduces the relative humidity of the air within a sealed electronic assembly. While the thermoelectric dehumidifier is primarily shown and described in conjunction with an antenna array enclosure, it is understood that the invention is also applicable to other enclosures in which it is desirable to reduce the relative humidity, such as enclosures for a receiver/exciter, a high power transformer, and AC/DC power.
In one embodiment, a thermoelectric dehumidifier in accordance with the present invention includes at least one thermoelectric chiller element disposed in a sealed region defined by opposing walls. The opposing walls can correspond to a hot plate facing an interior of an enclosure in which the thermoelectric dehumidifier is located and to a coldplate facing an exterior of the enclosure. The thermoelectric dehumidifier device can include a gutter at a bottom of the coldplate for collecting condensate on the coldplate.
In operation, the thermoelectric chiller elements are energized with a direct current signal that is effective to cool the coldplate to a predetermined temperature. Moisture in the air within the relatively sealed enclosure condenses on the coldplate and travels to the gutter. The collected moisture ultimately drains to an exterior of the enclosure to reduce the relative humidity within the enclosure.
An antenna array in accordance with the present invention can include a thermoelectric dehumidifier for extracting moisture from the array enclosure. In one embodiment, the thermoelectric dehumidifier is located proximate an enclosure wall. A drainage tube extends from a gutter for draining condensate from the array interior. The thermoelectric dehumidifier reduces the relative humidity within the array enclosure.